Methods of making high Q modified barium magnesium tantalate

ABSTRACT

Disclosed are embodiments of making a barium magnesium tantalate. The method can include providing barium magnesium tantalate and incorporating one of Ba2MgWO6, Ba8LiTa5WO24, Ba8LiTa5WO24, Ba2MgWO6, Ba3LaTa3O12, Ba8LiTa5WO24, BaLaLiWO6, Ba4Ta2WO12, Ba2La2MgW2O12, BaLaLiWO6, Sr3LaTa3O12, and SrLaTaO12 into the barium magnesium tantalate to form a solid solution having a high Q value.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Field

This disclosure generally relates to the use of modified bariummagnesium tantalate to attain ultra-high Q values.

Description of the Related Art

There is a paucity of ceramic material solutions which have sufficient Qvalues for frequencies up to 10 GHz. However, as the wirelesscommunication industry explores making use of frequency bands above 10GHz in a quest for more spectrum, such as for 5G applications, there isa need for ceramic materials with sufficient Q values in these highfrequencies for the formation of resonators and other filters.

Previous solutions were based on either barium zinc tantalate or bariummagnesium tantalate though barium zinc tantalate does not havesufficient high frequency (6-10 GHz) Q values. On the other hand, bariummagnesium tantalate has been shown to have acceptable Q values whendoped with tin. However, tin is very difficult to process consistentlydue to its high volatility along with the high temperatures required fordensification.

SUMMARY

Disclosed herein are embodiments of a high Q ceramic material comprisingbarium magnesium tantalate and one of a complex tungsten oxide compound,a hexagonal perovskite crystal structure, or a double perovskite crystalstructure incorporated into the barium magnesium tantalate to form acomposite material having a high Q value of greater than 12000 at about10 GHz.

In some embodiments, the high Q ceramic material does not include tin.In some embodiments, the complex tungsten oxide can be incorporated intothe barium magnesium tantalate. In some embodiments, between 3 wt. % and5 wt. % of the complex tungsten oxide can be incorporated into thebarium magnesium tantalate.

In some embodiments, the material can further include MgTa₂O₆incorporated into the barium magnesium tantalate.

In some embodiments, the complex tungsten oxide compound, the hexagonalperovskite crystal structure, or the double perovskite crystal structurecan be selected from the group consisting of Ba₂MgWO₆, Ba₈LiTa₅WO₂₄,Ba₈LiTa₅WO₂₄, Ba₂MgWO₆, Ba₃LaTa₃O₁₂, Ba₈LiTa₅WO₂₄, BaLaLiWO₆,Ba₄Ta₂WO₁₂, Ba₂La₂MgW₂O₁₂, BaLaLiWO₆, Sr₃LaTa₃O₁₂, and SrLaTaO₁₂.

In some embodiments, the hexagonal perovskite crystal structure can beincorporated into the barium magnesium tantalate. In some embodiments,about 5 wt. % of the hexagonal perovskite crystal structure can beincorporated into the barium magnesium tantalate. In some embodiments,the material can further include MgTa₂O₆ incorporated into the bariummagnesium tantalate.

In some embodiments, the composite material can contain at least 95%barium magnesium tantalate. In some embodiments, the composite materialcan contain at least 97% barium magnesium tantalate.

In some embodiments, the composite material can have a dielectricconstant of at least 25. The high Q ceramic material of claim 1 whereinthe composite material has a Q value of greater than 17000 at about 10GHz. In some embodiments, the composite material can include 95 wt. %Ba₃MgTa₂O₉+5 wt. % Ba₄Ta₂WO₁₂+0.2 weight % MgTa₂O₆ or 95 wt. %Ba₃MgTa₂O₉+5 wt. % Ba₄Ta₂WO₁₂+0.5 weight % MgTa₂O₆.

Also disclosed herein are embodiments of a method of making a high Qceramic material comprising providing barium magnesium tantalate, andincorporating one of a complex tungsten oxide compound, a hexagonalperovskite crystal structure, or a double hexagonal perovskite crystalstructure into the barium magnesium tantalate to form a solid solutionhaving a high Q value of greater than 12000 at about 10 GHz.

Further disclosed herein are embodiments of a dielectric resonator orisolator for applications above 10 GHz, the dielectric resonatorcomprising barium magnesium tantalate and one of a complex tungstenoxide compound. a hexagonal perovskite crystal structure, or a doublehexagonal perovskite crystal structure incorporated into the bariummagnesium tantalate to form a composite material having a high Q valueof greater than 12000 at 10 GHz. In some embodiments, the dielectricresonator can be configured to be used at frequencies of about 10 GHzand above.

Disclosed are embodiments of a cellular base station including the highQ ceramic material discussed herein. Disclosed are embodiments of amillimeter wave filter including the high Q ceramic material discussedherein. Disclosed are embodiments of a collision avoidance systemincluding the high Q ceramic material discussed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows how materials having one or more featuresdescribed herein can be designed, fabricated, and used.

FIG. 2 is a schematic design of one embodiment of a communicationnetwork.

FIG. 3 illustrates an example process flow for making an embodiment of acomposite ceramic material having one or more features described herein.

FIG. 4 shows a process that can be implemented to fabricate a compositeceramic material having one or more features as described herein.

FIG. 5 shows a process that can be implemented to form a shaped objectfrom powder material described herein.

FIG. 6 shows examples of various stages of the process of FIG. 5 .

FIG. 7 shows a process that can be implemented to sinter formed objectssuch as those formed in the example of FIGS. 5 and 6 .

FIG. 8 shows examples of various stages of the process of FIG. 7 .

FIG. 9 illustrates an embodiment of a power amplifier module which canuse embodiments of the disclosed material.

FIG. 10 illustrates an embodiment of a wireless device which can useembodiments of the disclosed material.

FIG. 11 illustrates a perspective view of a cellular antenna basestation incorporating embodiments of the disclosure.

FIG. 12 illustrates a schematic of a telecommunication base stationsystem incorporating an embodiment of a composite ceramic materialdisclosed herein.

FIG. 13 illustrates housing components of a base station incorporatingembodiments of the disclosed material.

FIG. 14 illustrates a cavity filter used in a base station incorporatingembodiments of the material disclosed herein.

DETAILED DESCRIPTION

Disclosed herein are embodiments of ceramic materials, in particulardoped or modified barium magnesium tantalate ceramic materials, whichcan have extremely high Q values. The advantageous properties of theceramic materials can be achieved by doping the barium magnesiumtantalate structure with small amounts of other materials, thusstabilizing the ceramic for use at high frequencies. The stabilizationand high Q value achieved by embodiments of the disclosure can beadvantageous for many different technologies, especially for radiofrequency applications in the high frequency ranges (>10 GHz), 5G, andcellular communications. Further, embodiments of the disclosed materialcan be used for millimeter wave filters and collision avoidance systems.Additionally, the use of any tin in the material can be avoided,providing for easier and more consistent processing.

FIG. 1 schematically shows how one or more chemical elements (block 1),chemical compounds (block 2), chemical substances (block 3) and/orchemical mixtures (block 4) can be processed to yield one or morematerials (block 5) having one or more features described herein. Insome embodiments, such materials can be formed into ceramic materials(block 6) configured to include a desirable dielectric property (block7), a magnetic property (block 8) and/or an advanced material property(block 9).

In some embodiments, a material having one or more of the foregoingproperties can be implemented in applications (block 10) such asradio-frequency (RF) application. Such applications can includeimplementations of one or more features as described herein in devices12. In some applications, such devices can further be implemented inproducts 11. Examples of such devices and/or products are describedherein.

Ultra-High Q Dielectric Materials

Embodiments of the disclosure can be used to prepare ceramic materialswith ultra-high Q values, making them especially useful in the highfrequency antenna field and for 5G applications.

In particular, barium magnesium tantalate, for example having theformula Ba₃MgTa₂O₉, Ba₃NiTa₂O₉, or Ba₃CoTa₂O₉, may be used as the baseof the material. In some embodiments, the barium magnesium tantalate canhave a 2:1 ordered hexagonal perovskite crystal structure, though theparticular structure is not limiting. Other material(s) can then beincorporated into the crystal structure of the barium magnesiumtantalate to improve the Q value of the final material, as well as toprovide other advantageous properties. The other materials can beincorporated into the structure by altering the initial material mix orby separately synthesizing the base material and the additive material.

Embodiments of the disclosure can be particularly useful as tin (Sn) canbe avoided, and thus the final composite material may include no tin.Previously, tin additives provided a way of stabilizing lossy anti-phasedomains in barium magnesium tantalate. However, embodiments of thedisclosure include tungstates with their cation vacancies diffuse toanti-phase domains stabilizing removing the dielectric losses caused bythe anti-phase domains. Thus, tin is not needed to stabilize the lossyanti-phase domains. This advantageously improves manufacturingprocessing, as tin is highly volatile and difficult to process as at theextremely high firing temperatures required. Thus, non-tin additives canbe incorporated into the barium magnesium tantalate to achieve high Qmaterials.

Accordingly, two methods of improving the Q values of barium magnesiumtantalate are discussed below. The first is through the inclusion ofcomplex tungsten oxide compounds. Example of this can include complextungsten(III) oxide, tungsten(IV) oxide, and tungsten (VI). In someembodiments, complex tungsten oxide compounds can be defined as having acrystal structure of hexagonal perovskites which are B cation deficientrelative to the stoichiometric perovskite structure. These can beincorporated into the base barium magnesium tantalate structure byaltering the initial material mix or by separately synthesizing the basematerial and the additive material.

The second method is through the inclusion of materials having a doubleperovskite or hexagonal perovskite crystal structure. The doubleperovskite structure is so named because the unit cell of is twice thatof perovskite. It has the same architecture of 12 coordinate A sites and6 coordinate B sites, but two cations are ordered on the B site.Hexagonal perovskites can include hexagonal close packing structures.

Both the complex tungsten oxide and double/hexagonal perovskite crystalstructure can modify the basic barium magnesium tantalate crystalstructure by entering into solid solution with the barium magnesiumtantalate. In some embodiments, multiple additional materials can beincorporated into the barium magnesium tantalate (such as both a complexoxide and a double/hexagonal perovskite crystal structure).

Accordingly, a number of different materials can be incorporated into asolid solution with the barium magnesium tantalate, such as, but notlimited to, Ba₂MgWO₆, Ba₈LiTa₅WO₂₄, Ba₈LiTa₅WO₂₄, Ba₂MgWO₆, Ba₃LaTa₃O₁₂,Ba₈LiTa₅WO₂₄, BaLaLiWO₆, Ba₄Ta₂WO₁₂, Ba₂La₂MgW₂O₁₂, BaLaLiWO₆,Sr₃LaTa₃O₁₂, and SrLaTaO₁₂. In some embodiments, hexagonal perovskiteswhich are B cation deficient relative to the stoichiometric perovskitestructure could be used. However, it will be understood that othercomplex oxides and double/hexagonal perovskite crystal structures can beincorporated as well.

In some embodiments, 90 wt. % or greater (or about 90 wt. % or greater),95 wt. % or greater (or about 95 wt. % or greater), 97 wt. % or greater(or about 97 wt. % or greater), or 99 wt. % or greater (or about 99 wt.% or greater) of barium magnesium tantalate can be the base material.For the additives, between 3 wt. % and 5 wt. % (or between about 3 wt. %and about 5 wt. %) of the materials can be incorporated into the bariummagnesium tantalate.

Further, in some embodiments MgTa₂O₆ can be added into the bariummagnesium tantalate along with the inclusions. This can be incorporatedinto the structure by altering the initial material mix or by separatelysynthesizing the base material and the additive material. This materialmay effectively make the barium magnesium tantalate barium deficient andcan induce vacant cation sites in the perovskite structure. In someembodiments, between 0.1 and 0.6 wt. % of the MgTa₂O₆ can be added. Insome embodiments, between 0.1 and 5.0 wt. % of the MgTa₂O₆ can be added.

Accordingly, embodiments of the disclosure can achieve high frequency Qvalues much greater than barium zinc tantalate based solutions (100000at 10 GHz) and can be much easier to process than tin-doped bariummagnesium tantalate based solutions. In particular, the added inclusionsmay be able to settle at lossy anti-phase domain boundaries andstabilize them so that they no longer become lossy at high frequencies.

Table I lists a number of different ceramic embodiments along with theirrespective properties. The barium magnesium tantalate listed in thetable can also be replaced with the other barium magnesium tantalateembodiments discussed above.

TABLE I Ceramic Material Formulations and Properties QF DensityDielectric Temp. Coef. Frequency Product Formula (g/cc) Constant (ppm/°C.) Q (GHz) (GHz) 97 wt. % Ba₃MgTa₂O₉ + 7.28 23.19 6436 10.86 69894.96 3wt. % Ba₂MgWO₆ 95 wt. % Ba₃MgTa₂O₉ + 7.62 24.94 1.7 11569 10.63122978.47 5 wt. % Ba₈LiTa₅WO₂₄ 95 wt. % Ba₃MgTa₂O₉ + 7.6 24.72 0.7511270 10.69 120476.3 5 wt. % Ba₄Ta₂WO₁₂ 95 wt. % Ba₃MgTa₂O₉ + 7.62 25.7113.7 14953 10.31 154165.43 5 wt. % Ba₃LaTa₃O₁₂ 95 wt. % Ba₃MgTa₂O₉ +6.81 21.3 917 5 wt. % BaLaLiWO₆ 95 wt. % Ba₃MgTa₂O₉ + 6.79 21.25 14.535585 5 wt. % Ba₂La₂MgW₂O₁₂ 95 wt. % Ba₃MgTa₂O₉ + 7.58 25.62 19.31 1030310.3 106120.9 5 wt. % Sr₃LaTa₃O₁₂

Accordingly, the above Table I illustrates different properties ofembodiments of the disclosed high Q materials at frequencies of 10 GHz(or frequencies of about 10 GHz). Q is the quality factor at aparticular frequency (listed in the table) and Qf product is the Q valuemultiplied by the particular frequency listed in the table.

In some embodiments, the material can achieve a Qf of greater than100000 (or greater than about 100000). In some embodiments, the materialcan achieve a Qf of greater than 125000 (or greater than about 125000).In some embodiments, the material can achieve a Qf of greater than150000 (or greater than about 150000). In some embodiments, the materialcan achieve a Qf of greater than 175000 (or greater than about 175000).In some embodiments, the material can achieve a Qf of less than 200000(or greater than about 200000). In some embodiments, the material canachieve a Qf of less than 190000 (or greater than about 190000). In someembodiments, the material can achieve a Qf of less than 180000 (orgreater than about 180000). The Qfs described in this paragraph are fora frequency of about 10 GHz. The frequency can range from about 10 toabout 11 GHz.

In some embodiments, the material can have a Q of greater than 10000 (orgreater than about 10000). In some embodiments, the material can have aQ of greater than 12000 (or greater than about 12000). In someembodiments, the material can have a Q of greater than 14000 (or greaterthan about 14000). In some embodiments, the material can have a Q ofgreater than 16000 (or greater than about 16000). In some embodiments,the material can have a Q of greater than 18000 (or greater than about18000). In some embodiments, the material can have a Q of greater lessthan 20000 (or less than about 20000). In some embodiments, the materialcan have a Q of greater less than 19000 (or less than about 19000). Insome embodiments, the material can have a Q of greater less than 18000(or less than about 18000).

In some embodiments, the material can have a temperature coefficient ofbetween −20 ppm/deg. C. to +20 ppm/deg. C. (or between about −20ppm/deg. C. to about +20 ppm/deg. C.). In some embodiments, the materialcan have a temperature coefficient of between −15 ppm/deg. C. to +15ppm/deg. C. (or between about −15 ppm/deg. C. to about +15 ppm/deg. C.).In some embodiments, the material can have a temperature coefficient ofbetween −10 ppm/deg. C. to +10 ppm/deg. C. (or between about −10ppm/deg. C. to about +10 ppm/deg. C.). In some embodiments, the materialcan have a temperature coefficient of between −5 ppm/deg. C. to +5ppm/deg. C. (or between about −5 ppm/deg. C. to about +5 ppm/deg. C.).In some embodiments, the material can have a temperature coefficient ofbetween −1 ppm/deg. C. to +1 ppm/deg. C. (or between about −1 ppm/deg.C. to about +1 ppm/deg. C.).

Thus, as shown in the above table, embodiments of the disclosure canhave high dielectric constants and Q values, making the materialparticularly suitable for high frequency applications. In someembodiments, the material can have a Qf of 200,000 or greater. Inparticular, embodiments of the disclosure can be used as dielectricresonators, in particular to frequencies>10 GHz. Further, embodiments ofthe disclosure can be used as millimeter wave filters and for collisionavoidance systems.

Embodiments of the disclosure can be used in collision avoidance systemsas a filter for high frequency, short range signals typically in the10-100 GHz range used for modern collision avoidance systems.

Further, embodiments of the material can be incorporated into millimeterwave filters operating at frequencies of 10 GHz or above (whereas mostmicrowave filters operate from 700 MHz to 3 GHz). Thus, embodiments ofthe disclosure can be advantageous in the 3-6 GHz range, such as for 5Gcellular systems. 5G technology is also referred to as 5G New Radio(NR). Additionally, the material can have applications for millimeterwave (mmW) frequencies/communications at 6 GHz and above. In someembodiments, it may be useful for frequencies such as 26 GHz and above.In some embodiments, communications systems using millimeter wavecarries can operate at frequencies of between 30 GHz to 300 GHz.

Preliminary specifications for 5G NR support a variety of features, suchas communications over millimeter wave spectrum, beam formingcapability, high spectral efficiency waveforms, low latencycommunications, multiple radio numerology, and/or non-orthogonalmultiple access (NOMA). Although such RF functionalities offerflexibility to networks and enhance user data rates, supporting suchfeatures can pose a number of technical challenges.

The teachings herein are applicable to a wide variety of communicationsystems, including, but not limited to, communication systems usingadvanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro,and/or 5G NR.

FIG. 2 is a schematic diagram of one example of a communication network13. The communication network 13 includes a macro cell base station 14,a mobile device 15, a small cell base station 16, and a stationarywireless device 17. The material disclosed herein can be incorporatedinto a number of components of the network, including the base stationsand devices. For example, as discussed below, embodiments of thematerial can be formed into a resonator for incorporation into awireless network.

The illustrated communication network 13 of FIG. 2 supportscommunications using a variety of technologies, including, for example,4G LTE, 5G NR, and wireless local area network (WLAN), such as Wi-Fi.Although various examples of supported communication technologies areshown, the communication network 13 can be adapted to support a widevariety of communication technologies.

As shown in FIG. 2 , the mobile device 15 communicates with the macrocell base station 14 over a communication link that uses a combinationof 4G LTE and 5G NR technologies. The mobile device 15 alsocommunications with the small cell base station 16. In the illustratedexample, the mobile device 15 and small cell base station 16 communicateover a communication link that uses 5G NR, 4G LTE, and Wi-Fitechnologies.

In certain implementations, the mobile device 15 communicates with themacro cell base station 14 and the small cell base station 16 using 5GNR technology over one or more frequency bands that are less than 6Gigahertz (GHz). In one embodiment, the mobile device 15 supports a HPUEpower class specification.

The illustrated small cell base station 16 also communicates with astationary wireless device 17. The small cell base station 16 can beused, for example, to provide broadband service using 5G NR technologyover one or more frequency bands above 6 GHz, including, for example,millimeter wave bands in the frequency range of 30 GHz to 300 GHz.

In certain implementations, the small cell base station 16 communicateswith the stationary wireless device 17 using beamforming. For example,beamforming can be used to focus signal strength to overcome pathlosses, such as high loss associated with communicating over millimeterwave frequencies.

The communication network 13 of FIG. 2 includes the macro cell basestation 14 and the small cell base station 16. In certainimplementations, the small cell base station 16 can operate withrelatively lower power, shorter range, and/or with fewer concurrentusers relative to the macro cell base station 14. The small cell basestation 16 can also be referred to as a femtocell, a picocell, or amicrocell.

Although the communication network 13 is illustrated as including twobase stations, the communication network 13 can be implemented toinclude more or fewer base stations and/or base stations of other types.

The communication network 13 of FIG. 2 is illustrated as including onemobile device 15 and one stationary wireless device 17. The mobiledevice 15 and the stationary wireless device 17 illustrate two examplesof user devices or user equipment (UE). Although the communicationnetwork 13 is illustrated as including two user devices, thecommunication network 13 can be used to communicate with more or feweruser devices and/or user devices of other types. For example, userdevices can include mobile phones, tablets, laptops, IoT devices,wearable electronics, and/or a wide variety of other communicationsdevices.

User devices of the communication network 13 can share available networkresources (for instance, available frequency spectrum) in a wide varietyof ways.

Preparation of the Composite Ceramic Materials:

The preparation of embodiments of the above-discussed compositematerials can be accomplished by using known ceramic techniques. Aparticular example of the process flow is illustrated in FIG. 3 .

As shown in FIG. 3 , the process begins with step 106 for weighing theraw material. The raw material may include barium carbonate, magnesiumoxide, tantalum pentoxide and other oxides from the “additive” compoundssuch as lithium carbonate and tungsten oxide. In addition, organic basedmaterials may be used in a sol gel process for ethoxides and/oracrylates or citrate based techniques may be employed. Other knownmethods in the art such as co-precipitation of hydroxides, sol-gel, orlaser ablation may also be employed as a method to obtain the materials.The amount and selection of raw material depends on the specificformulation.

After the raw materials are weighed, they are blended in Step 108 usingmethods consistent with the current state of the ceramic art, which caninclude aqueous blending using a mixing propeller, or aqueous blendingusing a vibratory mill with steel or zirconia media. In someembodiments, a glycine nitrate or spray pyrolysis technique may be usedfor blending and simultaneously reacting the raw materials.

The blended oxide is subsequently dried in Step 110, which can beaccomplished by pouring the slurry into a pane and drying in an oven,preferably between 100-400° C. or by spray drying, or by othertechniques known in the art.

The dried oxide blend is processed through a sieve in Step 112, whichhomogenizes the powder and breaks up soft agglomerates that may lead todense particles after calcining.

The material is subsequently processed through a pre-sintering calciningin Step 114. Preferably, the material is loaded into a container such asan alumina or cordierite sagger and heat treated in the range of about800-1600° C.

After calcining, the material is milled in Step 116, preferably in avibratory mill, an attrition mill, a jet mill or other standardcomminution technique to reduce the median particle size into the rangeof about 0.1 to 10.0 microns, though in some embodiments larger orsmaller sizes may be used as well. Milling is preferably done in a waterbased slurry but may also be done in ethyl alcohol or another organicbased solvent.

The material is subsequently spray dried in Step 118. During the spraydrying process, organic additives such as binders and plasticizers canbe added to the slurry using techniques known in the art. The materialis spray dried to provide granules amenable to pressing, preferably inthe range of about 10 microns to 150 microns in size.

The spray dried granules are subsequently pressed in Step 120,preferably by uniaxial or isostatic pressing to achieve a presseddensity to as close to 60% of the x-ray theoretical density as possible.In addition, other known methods such as tape casting, tape calendaringor extrusion may be employed as well to form the unfired body.

The pressed material is subsequently processed through a calciningprocess in Step 122. Preferably, the pressed material is placed on asetter plate made of material such as alumina which does not readilyreact with the garnet material. The setter plate is heated in a periodickiln or a tunnel kiln in air or pressure oxygen in the range of betweenabout 850° C.-1600° C. to obtain a dense ceramic compact. Other knowntreatment techniques, such as induction heat, hot pressing, fast firing,or assisted fast firing, may also be used in this step. In someembodiments, a density having >98% of the theoretical density can beachieved.

The dense ceramic compact is machined in the Step 124 to achievedimensions suitable or the particular applications.

Fabrication of Radiofrequency Devices

FIGS. 4-8 show examples of how radiofrequency devices having one or morefeatures as described herein can be fabricated. FIG. 4 shows a process20 that can be implemented to fabricate a ceramic material having one ormore of the foregoing properties. In block 21, powder can be prepared.In block 22, a shaped object can be formed from the prepared powder. Inblock 23, the formed object can be sintered. In block 24, the sinteredobject can be finished to yield a finished ceramic object having one ormore desirable properties.

In implementations where the finished ceramic object is part of adevice, the device can be assembled in block 25. In implementationswhere the device or the finished ceramic object is part of a product,the product can be assembled in block 26.

FIG. 4 further shows that some or all of the steps of the exampleprocess 20 can be based on a design, specification, etc. Similarly, someor all of the steps can include or be subjected to testing, qualitycontrol, etc.

In some implementations, the powder preparation step (block 21) of FIG.4 can be performed by the example process described in reference to FIG.3 . Powder prepared in such a manner can include one or more propertiesas described herein, and/or facilitate formation of ceramic objectshaving one or more properties as described herein.

In some implementations, powder prepared as described herein can beformed into different shapes by different forming techniques. By way ofexamples, FIG. 5 shows a process 50 that can be implemented topress-form a shaped object from a powder material prepared as describedherein. In block 52, a shaped die can be filled with a desired amount ofthe powder. In FIG. 6 , configuration 60 shows the shaped die as 61 thatdefines a volume 62 dimensioned to receive the powder 63 and allow suchpower to be pressed. In block 53, the powder in the die can becompressed to form a shaped object. Configuration 64 shows the powder inan intermediate compacted form 67 as a piston 65 is pressed (arrow 66)into the volume 62 defined by the die 61. In block 54, pressure can beremoved from the die. In block 55, the piston (65) can be removed fromthe die (61) so as to open the volume (62). Configuration 68 shows theopened volume (62) of the die (61) thereby allowing the formed object 69to be removed from the die. In block 56, the formed object (69) can beremoved from the die (61). In block 57, the formed object can be storedfor further processing.

In some implementations, formed objects fabricated as described hereincan be sintered to yield desirable physical properties as ceramicdevices. FIG. 7 shows a process 70 that can be implemented to sintersuch formed objects. In block 71, formed objects can be provided. Inblock 72, the formed objects can be introduced into a kiln. In FIG. 8 ,a plurality of formed objects 69 are shown to be loaded into a sinteringtray 80. The example tray 80 is shown to define a recess 83 dimensionedto hold the formed objects 69 on a surface 82 so that the upper edge ofthe tray is higher than the upper portions of the formed objects 69.Such a configuration allows the loaded trays to be stacked during thesintering process. The example tray 80 is further shown to definecutouts 83 at the side walls to allow improved circulation of hot gas atwithin the recess 83, even when the trays are stacked together. FIG. 8further shows a stack 84 of a plurality of loaded trays 80. A top cover85 can be provided so that the objects loaded in the top tray generallyexperience similar sintering condition as those in lower trays.

In block 73, heat can be applied to the formed objects so as to yieldsintered objects. Such application of heat can be achieved by use of akiln. In block 74, the sintered objects can be removed from the kiln. InFIG. 8 , the stack 84 having a plurality of loaded trays is depicted asbeing introduced into a kiln 87 (stage 86 a). Such a stack can be movedthrough the kiln (stages 86 b, 86 c) based on a desired time andtemperature profile. In stage 86 d, the stack 84 is depicted as beingremoved from the kiln so as to be cooled.

In block 75, the sintered objects can be cooled. Such cooling can bebased on a desired time and temperature profile. In block 206, thecooled objects can undergo one or more finishing operations. In block207, one or more tests can be performed.

Heat treatment of various forms of powder and various forms of shapedobjects are described herein as calcining, firing, annealing, and/orsintering. It will be understood that such terms may be usedinterchangeably in some appropriate situations, in context-specificmanners, or some combination thereof.

Application of the Material

FIGS. 9 and 10 respectively illustrate a power amplifier module 1010 andwireless device 1011 which can include one or more radio frequencydevices implemented using any of the methods, materials, and devices ofthe present disclosure. For instance, the power amplifier module 1010and the wireless device 1011 can include one or more antennas,transformers, inductors, circulators, absorbers, or other RF devices orother devices implemented according to the present disclosure, includingdevices incorporating an embodiment of the disclosed composite ceramic.

FIG. 9 is a schematic diagram of a power amplifier module (PAM) 1010 foramplifying a radio frequency (RF) signal. The illustrated poweramplifier module 1010 amplifies an RF signal (RF_IN) to generate anamplified RF signal (RF_OUT).

FIG. 10 is a schematic block diagram of an example wireless or mobiledevice 1011. The example wireless device 1011 depicted in FIG. 10 canrepresent a multi-band and/or multi-mode device such as amulti-band/multi-mode mobile phone. By way of examples, Global Systemfor Mobile (GSM) communication standard is a mode of digital cellularcommunication that is utilized in many parts of the world. GSM modemobile phones can operate at one or more of four frequency bands: 850MHz (approximately 824-849 MHz for Tx, 869-894 MHz for Rx), 900 MHz(approximately 880-915 MHz for Tx, 925-960 MHz for Rx), 1800 MHz(approximately 1710-1785 MHz for Tx, 1805-1880 MHz for Rx), and 1900 MHz(approximately 1850-1910 MHz for Tx, 1930-1990 MHz for Rx). Variationsand/or regional/national implementations of the GSM bands are alsoutilized in different parts of the world.

Code division multiple access (CDMA) is another standard that can beimplemented in mobile phone devices. In certain implementations, CDMAdevices can operate in one or more of 800 MHz, 900 MHz, 1800 MHz and1900 MHz bands, while certain W-CDMA and Long Term Evolution (LTE)devices can operate over, for example, 22 or more radio frequencyspectrum bands.

One or more features of the present disclosure can be implemented in theforegoing example modes and/or bands, and in other communicationstandards. For example, 802.11, 2G, 3G, 4G, LTE, and Advanced LTE arenon-limiting examples of such standards. To increase data rates, thewireless device 1011 can operate using complex modulated signals, suchas 64 QAM signals.

In certain embodiments, the wireless device 1011 can include switches1012, a transceiver 1013, an antenna 1014, power amplifiers 1017 a, 1017b, a control component 1018, a computer readable medium 1019, aprocessor 1020, a battery 1021, and a power management system 1030, anyof which can include embodiments of the disclosed material.

The transceiver 1013 can generate RF signals for transmission via theantenna 1014. Furthermore, the transceiver 1013 can receive incoming RFsignals from the antenna 1014.

It will be understood that various functionalities associated with thetransmission and receiving of RF signals can be achieved by one or morecomponents that are collectively represented in FIG. 10 as thetransceiver 1013. For example, a single component can be configured toprovide both transmitting and receiving functionalities. In anotherexample, transmitting and receiving functionalities can be provided byseparate components.

Similarly, it will be understood that various antenna functionalitiesassociated with the transmission and receiving of RF signals can beachieved by one or more components that are collectively represented inFIG. 10 as the antenna 1014. For example, a single antenna can beconfigured to provide both transmitting and receiving functionalities.In another example, transmitting and receiving functionalities can beprovided by separate antennas. In yet another example, different bandsassociated with the wireless device 1011 can operate using differentantennas.

In FIG. 10 , one or more output signals from the transceiver 1013 aredepicted as being provided to the antenna 1014 via one or moretransmission paths 1015. In the example shown, different transmissionpaths 1015 can represent output paths associated with different bandsand/or different power outputs. For instance, the two example poweramplifiers 1017 a, 1017 b shown can represent amplifications associatedwith different power output configurations (e.g., low power output andhigh power output), and/or amplifications associated with differentbands. Although FIG. 10 illustrates a configuration using twotransmission paths 1015 and two power amplifiers 1017 a, 1017 b, thewireless device 1011 can be adapted to include more or fewertransmission paths 1015 and/or more or fewer power amplifiers.

In FIG. 10 , one or more detected signals from the antenna 1014 aredepicted as being provided to the transceiver 1013 via one or morereceiving paths 1016. In the example shown, different receiving paths1016 can represent paths associated with different bands. For example,the four example receiving paths 1016 shown can represent quad-bandcapability that some wireless devices are provided with. Although FIG.10 illustrates a configuration using four receiving paths 1016, thewireless device 1011 can be adapted to include more or fewer receivingpaths 1016.

To facilitate switching between receive and transmit paths, the switches1012 can be configured to electrically connect the antenna 1014 to aselected transmit or receive path. Thus, the switches 1012 can provide anumber of switching functionalities associated with operation of thewireless device 1011. In certain embodiments, the switches 1012 caninclude a number of switches configured to provide functionalitiesassociated with, for example, switching between different bands,switching between different power modes, switching between transmissionand receiving modes, or some combination thereof. The switches 1012 canalso be configured to provide additional functionality, includingfiltering and/or duplexing of signals.

FIG. 10 shows that in certain embodiments, a control component 1018 canbe provided for controlling various control functionalities associatedwith operations of the switches 1012, the power amplifiers 1017 a, 1017b, the power management system 1030, and/or other operating components.

In certain embodiments, a processor 1020 can be configured to facilitateimplementation of various processes described herein. The processor 1020can implement various computer program instructions. The processor 1020can be a general purpose computer, special purpose computer, or otherprogrammable data processing apparatus.

In certain embodiments, these computer program instructions may also bestored in a computer-readable memory 1019 that can direct the processor1020 to operate in a particular manner, such that the instructionsstored in the computer-readable memory 1019.

The illustrated wireless device 1011 also includes the power managementsystem 1030, which can be used to provide power amplifier supplyvoltages to one or more of the power amplifiers 1017 a, 1017 b. Forexample, the power management system 1030 can be configured to changethe supply voltages provided to the power amplifiers 1017 a, 1017 b toimprove efficiency, such as power added efficiency (PAE). The powermanagement system 1030 can be used to provide average power tracking(APT) and/or envelope tracking (ET). Furthermore, as will be describedin detail further below, the power management system 1030 can includeone or more low dropout (LDO) regulators used to generate poweramplifier supply voltages for one or more stages of the power amplifiers1017 a, 1017 b. In the illustrated implementation, the power managementsystem 1030 is controlled using a power control signal generated by thetransceiver 1013. In certain configurations, the power control signal isprovided by the transceiver 1013 to the power management system 1030over an interface, such as a serial peripheral interface (SPI) or MobileIndustry Processor Interface (MIPI).

In certain configurations, the wireless device 1011 may operate usingcarrier aggregation. Carrier aggregation can be used for both FrequencyDivision Duplexing (FDD) and Time Division Duplexing (TDD), and may beused to aggregate a plurality of carriers or channels, for instance upto five carriers. Carrier aggregation includes contiguous aggregation,in which contiguous carriers within the same operating frequency bandare aggregated. Carrier aggregation can also be non-contiguous, and caninclude carriers separated in frequency within a common band or indifferent bands.

Telecommunication Base Station

Circuits and devices having one or more features as described herein canbe implemented in RF applications such as a wireless base-station. Sucha wireless base-station can include one or more antennas configured tofacilitate transmission and/or reception of RF signals. Such antenna(s)can be coupled to circuits and devices having one or morecirculators/isolators as described herein.

Thus, in some embodiments, the above disclosed material can beincorporated into different components of a telecommunication basestation, such as used for cellular networks and wireless communications.An example perspective view of a base station 2000 is shown in FIG. 11 ,including both a cell tower 2002 and electronics building 2004. The celltower 2002 can include a number of antennas 2006, typically facingdifferent directions for optimizing service, which can be used to bothreceive and transmit cellular signals while the electronics building2004 can hold electronic components such as filters, amplifiers, etc.discussed below. Both the antennas 2006 and electronic components canincorporate embodiments of the disclosed ceramic materials.

FIG. 12 shows a schematic view of a base station such as shown in FIG.11 . As shown, the base station can include an antenna 412 that isconfigured to facilitate transmission and/or reception of RF signals.Such signals can be generated by and/or processed by a transceiver 414.For transmission, the transceiver 414 can generate a transmit signalthat is amplified by a power amplifier (PA) and filtered (Tx Filter) fortransmission by the antenna 412. For reception, a signal received fromthe antenna 412 can be filtered (Rx Filter) and amplified by a low-noiseamplifier (LNA) before being passed on to the transceiver 414. In theexample context of such Tx and Rx paths, circulators and/or isolators400 having one or more features as described herein can be implementedat or in connection with, for example, the PA circuit and the LNAcircuit. The circulators and isolators can include embodiments of thematerial disclosed herein. Further, the antennas can include thematerials disclosed herein, allowing them to work on higher frequencyranges.

FIG. 13 illustrates hardware 2010 that can be used in the electronicsbuilding 2004, and can include the components discussed above withrespect to FIG. 11 . For example, the hardware 2010 can be a basestation subsystem (BSS), which can handle traffic and signaling for themobile systems.

FIG. 14 illustrates a further detailing of the hardware 2010 discussedabove. Specifically, FIG. 14 depicts a cavity filter/combiner 2020 whichcan be incorporated into the base station. The cavity filter 2020 caninclude, for example, bandpass filters such as those incorporatingembodiments of the disclosed material, and can allow the output of twoor more transmitters on different frequencies to be combined.

From the foregoing description, it will be appreciated that inventiveceramics have advantageous properties and the method of manufacturing isdisclosed. While several components, techniques and aspects have beendescribed with a certain degree of particularity, it is manifest thatmany changes can be made in the specific designs, constructions andmethodology herein above described without departing from the spirit andscope of this disclosure.

Certain features that are described in this disclosure in the context ofseparate implementations can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations, one or more features from a claimed combination can, insome cases, be excised from the combination, and the combination may beclaimed as any subcombination or variation of any subcombination.

Moreover, while methods may be depicted in the drawings or described inthe specification in a particular order, such methods need not beperformed in the particular order shown or in sequential order, and thatall methods need not be performed, to achieve desirable results. Othermethods that are not depicted or described can be incorporated in theexample methods and processes. For example, one or more additionalmethods can be performed before, after, simultaneously, or between anyof the described methods. Further, the methods may be rearranged orreordered in other implementations. Also, the separation of varioussystem components in the implementations described above should not beunderstood as requiring such separation in all implementations, and itshould be understood that the described components and systems cangenerally be integrated together in a single product or packaged intomultiple products. Additionally, other implementations are within thescope of this disclosure.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include or do not include, certain features, elements,and/or steps. Thus, such conditional language is not generally intendedto imply that features, elements, and/or steps are in any way requiredfor one or more embodiments.

Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,”“about,” “generally,” and “substantially” as used herein represent avalue, amount, or characteristic close to the stated value, amount, orcharacteristic that still performs a desired function or achieves adesired result. For example, the terms “approximately”, “about”,“generally,” and “substantially” may refer to an amount that is withinless than or equal to 10% of, within less than or equal to 5% of, withinless than or equal to 1% of, within less than or equal to 0.1% of, andwithin less than or equal to 0.01% of the stated amount. If the statedamount is 0 (e.g., none, having no), the above recited ranges can bespecific ranges, and not within a particular % of the value. Forexample, within less than or equal to 10 wt./vol. % of, within less thanor equal to 5 wt./vol. % of, within less than or equal to 1 wt./vol. %of, within less than or equal to 0.1 wt./vol. % of, and within less thanor equal to 0.01 wt./vol. % of the stated amount.

Some embodiments have been described in connection with the accompanyingdrawings. The figures are drawn to scale, but such scale should not belimiting, since dimensions and proportions other than what are shown arecontemplated and are within the scope of the disclosed inventions.Distances, angles, etc. are merely illustrative and do not necessarilybear an exact relationship to actual dimensions and layout of thedevices illustrated. Components can be added, removed, and/orrearranged. Further, the disclosure herein of any particular feature,aspect, method, property, characteristic, quality, attribute, element,or the like in connection with various embodiments can be used in allother embodiments set forth herein. Additionally, it will be recognizedthat any methods described herein may be practiced using any devicesuitable for performing the recited steps.

While a number of embodiments and variations thereof have been describedin detail, other modifications and methods of using the same will beapparent to those of skill in the art. Accordingly, it should beunderstood that various applications, modifications, materials, andsubstitutions can be made of equivalents without departing from theunique and inventive disclosure herein or the scope of the claims.

What is claimed is:
 1. A method of making a high Q material comprising:providing barium magnesium tantalate; and incorporating one of Ba₂MgWO₆,Ba₈LiTa₅WO₂₄, Ba₃LaTa₃Q₁₂, BaLaLiWO₆, Ba₄Ta₂WO₁₂, Ba₂La₂MgW₂O₁₂,Sr₃LaTa₃Q₁₂, and SrLaTaO₁₂ into the barium magnesium tantalate to form asolid solution having a high Q value of greater than 12000 at about 10GHz.
 2. The method of claim 1 wherein the solid solution does notinclude tin.
 3. The method of claim 1 wherein the solid solutioncontains at least 95% barium magnesium tantalate.
 4. The method of claim1 wherein the solid solution contains at least 97% barium magnesiumtantalate.
 5. The method of claim 1 wherein the solid solution has adielectric constant of at least
 25. 6. The method of claim 1 furthercomprising incorporating MgTa₂O₆ into the barium magnesium tantalate. 7.The method of claim 1 wherein the solid solution has a Q value ofgreater than 17000 at about 10 GHz.
 8. The method of claim 1 furthercomprising incorporating the solid solution into a cellular basestation.
 9. The method of claim 1 further comprising incorporating thesolid solution into a millimeter wave filter.
 10. The method of claim 1further comprising incorporating the solid solution into a collisionavoidance system.
 11. The method of claim 1 further comprisingincorporating the solid solution into a resonator or isolator.
 12. Amethod of making a composite material, the method comprising: providingbarium magnesium tantalate; and incorporating one of Ba₂MgWO₆,Ba₈LiTa₅WO₂₄, Ba₃LaTa₃Q₁₂, BaLaLiWO₆, Ba₄Ta₂WO₁₂, Ba₂La₂MgW₂O₁₂,Sr₃LaTa₃Q₁₂, and SrLaTaO₁₂ into the barium magnesium tantalate to form acomposite material having a high Q value of greater than 12000 at about10 GHz.
 13. The method of claim 11 wherein the composite material doesnot include tin.
 14. The method of claim 11 wherein the compositematerial contains at least 95% barium magnesium tantalate.
 15. Themethod of claim 11 wherein the composite material contains at least 97%barium magnesium tantalate.
 16. The method of claim 11 wherein thecomposite material has a dielectric constant of at least
 25. 17. Themethod of claim 11 further comprising incorporating MgTa₂O₆ into thecomposite material.
 18. The method of claim 11 wherein the compositematerial has a Q value of greater than 17000 at about 10 GHz.
 19. Themethod of claim 11 further comprising incorporating the compositematerial into a cellular base station.
 20. The method of claim 11further comprising incorporating the composite material into a resonatoror isolator.